Reliability and long term stability of a digital pressure gauge (DPG) used as a standard- a case study

摘要

The current paper reports the stability of a pressure dynamometer with a full scale pressure of 60 bar over nine years of operation. Since the stability of this digital pressure gauge depends on factors like repeatability, hysteresis, non-linearity, relative deviation etc, a systematic study has been carried out on each of these components. Finally, a comparison of the calibration factors and the estimated expanded uncertainty is made from the collected nine years calibration database. It has been found that the performance of the equipment showed consistent results for about 5 years after which a slight shift in the parameters described above has set in. But, the overall performance of the equipment remains excellent over the period studied within the limit of experimental uncertainty.